Income Taxes - Tax Rates (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Effective Income Tax Rates [Abstract]
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities		$ 43
Discrete tax benefit		14
Effective Income Tax Rate	25.60%		44.20%	25.40%	33.90%
Adjustment to current income tax balance as a result of settlement		$ 29